Giant Neck Masses

A giant neck mass is an abnormal growth or mass that develops in the neck of a fetus. These rare birth defects can press against the fetal trachea (airway) and esophagus (food tube), putting the baby and the pregnancy at risk of serious complications, including life-threatening breathing problems at birth.

There is no known cause for this rare condition. Giant neck masses are typically an isolated condition and they can be difficult to treat.

Early diagnosis and careful delivery planning are critical to optimizing outcomes.

Types of Masses

The two most common types of giant neck masses are:

• Lymphatic malformations – a mass made up of an irregular grouping of blood vessels, lymphatic channels and veins caused by an abnormality in the development of the lymphatic system (lymphatic malformations are also known as lymphangiomas or cystic hygroma)
• Teratomas – a tumor made up of several different types of cells; small areas of cancerous tissue may be found in about 10-20% of fetuses with teratoma neck masses

In rarer cases, the giant neck mass may be caused by abnormalities such as neuroblastoma, cervical thymic cyst, or hemangioma. 

How does a giant neck mass affect my baby?

As the mass grows, it can compress nearby structures, distorting and obstructing the baby’s trachea and esophagus.

Risks to the baby and the pregnancy include:

• Life-threatening breathing problems at birth or breathing delays that put your baby at risk for brain injury at delivery
• Polyhydramnios, a buildup of amniotic fluid in the womb when the fetus is unable to swallow
• Preterm labor
• Pulmonary hypoplasia (small lungs), due to the giant neck mass preventing the fetus from breathing fully, stunting the growth of the lungs
• Soft trachea, if the compression prevents the breathing tube from developing normally
• Facial deformity and dysfunction, causing problems with eating and speech
• Hydrops fetalis (fetal hydrops), where fluid accumulates in different areas of the baby’s body during pregnancy and may be a sign of fetal heart failure
• Stillbirth

Prognosis

Babies with giant neck masses are at high risk of asphyxia (oxygen deprivation) at birth, leading to death or brain injury. Prognosis depends on the severity of the baby’s condition, the underlying cause of the neck mass, the timing of the diagnosis, and proper delivery planning and treatment.

Diagnosis

Giant fetal neck masses are typically detected during a routine ultrasound. If a neck mass is suspected or diagnosed, you may be referred to a fetal center for further assessment and specialized care.

At Texas Children’s Fetal Center, we arrange for you to visit as quickly as possible for a detailed evaluation by a team of specialists experienced in diagnosing and treating these rare birth defects, including maternal-fetal medicine (MFM) physicians, fetal imaging experts, neonatologists and surgeons.

Additional testing may include:

• High-resolution anatomy ultrasound to evaluate the mass and the baby’s condition and look for other abnormalities
• Ultra-fast MRI for a more detailed view of fetal anatomy and function, including the exact size, type and location of the mass and impact on surrounding structures
• Fetal echocardiogram to evaluate the baby’s heart
• Amniocentesis and chromosomal analysis to identify any chromosomal anomalies

Following this thorough evaluation, our specialists will meet with you about your results, answer any questions you have, and discuss delivery planning and treatment recommendations.

A Novel Diagnostic Tool, for Better Treatment Planning

Fetal MRI is used to determine whether a giant neck mass is compressing the trachea or esophagus.

Our specialists have developed a novel measurement called the tracheo-esophageal displacement index (TEDI) to help determine how far the fetal trachea has been moved from its normal location. Our treatment team uses this measurement and other characteristics to determine whether a treatment known as an EXIT procedure may be required at delivery.

Treatment During Pregnancy

You and your baby will be closely monitored throughout pregnancy with regular ultrasounds to assess the fetal neck mass and watch for signs of complications.

If polyhydramnios occurs (an excess accumulation of amniotic fluid), an amnioreduction procedure may be performed to remove the excess fluid and reduce the risks of preterm birth. The procedure is similar to an amniocentesis. In some cases, medication may be used to decrease the amniotic fluid level.

Surgery to remove the giant neck mass is typically performed after birth.

Delivery

Babies with giant fetal neck masses are at risk of breathing difficulties at birth. For the best possible outcome, we recommend delivery at a hospital with the expertise and resources required to manage these complicated deliveries, including the highest level neonatal intensive care unit (NICU).

If the baby’s airway is blocked, your doctor may recommend a cesarean section with an EXIT (ex-utero intrapartum treatment) procedure, a fetal surgery performed during delivery to ensure the baby isn’t deprived of oxygen at birth. Delivery should be carefully planned and coordinated with a team of specialists experienced in these procedures.  

EXIT Procedures – Fetal Surgery During Delivery

In an EXIT procedure, the mother’s abdomen and uterus are opened, as in a C-section, under general anesthesia. The baby’s head and part of the upper body are then delivered. The baby remains attached to the umbilical cord and placenta, to continue receiving life-sustaining oxygen from the mother, while steps are taken to provide the baby an airway for breathing at birth.

Treatment After Birth

Babies with a giant neck mass do not always require surgery. Treatment depends on the cause of the neck mass. For example, if the lesion is caused by a lymphatic malformation, it may be treated with medication (i.e. sirolimus). In other cases, surgery may be required to remove the giant neck mass. The timing of the surgery will depend on the baby’s condition.

Additional treatment strategies may include:

• Tracheostomy (breathing tube) to make breathing easier and allow the trachea time to harden, if needed
• Gastrostomy (feeding tube), for newborns unable to swallow because the esophagus was compressed
• Thyroid treatment if the baby’s thyroid is impacted by the neck mass
• Ongoing screening for possible recurrence of the neck mass

Expert Postnatal Care

A unique and distinct advantage for mothers delivering at Texas Children’s Pavilion for Women is our location inside one of the top children’s hospitals in the nation, for seamless access to the critical care services and specialists your child may need after birth.

For babies with giant neck masses, this means no transfers during critical postnatal periods. It also means that the pediatric specialists responsible for treating your child have been an integral part of their care team since before birth.

Our fetal center patients benefit from:

Texas Children’s Head and Neck Tumor Program - experts in the surgical care of children with benign and malignant masses in the head and neck.

Texas Children’s Vascular Anomalies Center - a multidisciplinary team of experts in the field of vascular malformations and vascular tumors, including specialists in dermatology, hematology/oncology, interventional radiology, otolaryngology, pathology, pediatric surgery and plastic surgery, and others.

Depending on your baby’s needs, his or her postnatal care team may include:

• Neonatologist
• Pediatric Surgeon
• Plastic Surgeon
• Otolaryngologist
• Speech Therapist

Why Texas Children’s Fetal Center?

• A single location for expert maternal, fetal and pediatric care. At Texas Children’s Hospital, you and your baby receive the specialized care required for the diagnosis and treatment of giant fetal neck masses all in one location, including immediate access to our level IV NICU, the highest level of care available for premature and critically ill newborns.
• A skilled, experienced team with proven outcomes. We have a dedicated team of maternal-fetal medicine specialists, fetal and pediatric surgeons, imaging experts, anesthesiologists, neonatologists, and others who work in concert to care for you and your baby every step of the way, using proven protocols we’ve developed over the years. With their combined expertise and unified approach, this team offers the best possible care for pregnancies and babies with giant neck masses.
• We care for your child’s needs at every stage of life. Our comprehensive approach starts with your first prenatal visit and continues through delivery, postnatal care, and throughout childhood, thanks to one of the nation’s leading teams of fetal and pediatrics specialists for the care and treatment of rare fetal birth defects.